A technique for forming a thin film transistor (TFT) with the use of a semiconductor thin film formed over a substrate having an insulating surface has attracted attention. A thin film transistor is applied to a wide range of electronic devices such as an integrated circuit (IC) or an image display device (display device).
As a material having semiconductor characteristics suitable for thin film transistors, a metal oxide has attracted attention, and thin film transistors in which a channel formation region is formed using such a metal oxide having semiconductor characteristics are known (see Patent Documents 1 and 2).
In addition, electronic devices with the use of thin film transistors have been used in a variety of places for a variety of applications and thus have been required to have various characteristics and shapes such as light weight, thinness, and impact resistance. Accordingly, electronic devices having functions for serving their intended purposes have been developed.
For example, as a semiconductor device which is provided for an amusement machine, a display whose display surface is curved so that players can experience stereoscopic effect has been reported (e.g., see Patent Document 3).